In times of crisis, solidarity means, first and foremost, continuing to hold our jobs and assume the responsibilities attached to it, the ones others count on us for. Society is founded on a distribution of tasks, itself based on regulations and on a certain degree of trust. If, of course, expressing opinions and engaging in debate is a healthy democratic practice, one must remember that having an opinion on someone else’s job is quite different from being able to actually handle it.
In times of crisis, some of us must continue to hold their jobs responsibly and professionally, at all costs, despite the difficulties and the criticism, and it’s the job of the rest of us to provide them with our support.
Providing constant, reliable electricity is one of these essential tasks. We, at the Voices, decided to do our part by addressing the necessary conditions of a reliable electric supply, and, in this way, thanking those we owe it to.
We asked two of our members, Jean Fluchere and Tanguy Firinga, to explain the little known conditions for grid stability. They represent the two generations most representative of the crisis. Both are tirelessly working at making the nuclear and power sectors better known and understood, both are confined.
We wish you all good health, the best of luck in organising yourselves and your loved ones and, of course, scrupulous compliance with the rules for security and confinement.
for the Voices
Covid 19, security of power supply and resilience
The European power system and the present crisis
The Covid-19 pandemic affecting the entire world population is without parallel since the Spanish flu epidemic of 1918-1919. Many countries have been obliged to put their populations under isolation in order to slow the spread of the Covid-19 virus.
In this situation, transport networks – water, energy (electricity and gas) and information (Internet, television, radio) – are of vital importance. These large-scale technical systems, all developed in the last century, are now an integral part of our daily lives, enabling us to live, and even work, almost without leaving home.
The “Electricity Fairy” has become indispensable for lighting, cooking, heating, refrigeration, communication, healthcare and even mobility. This is particularly so at present, especially for hospitals and other vital services intensely solicited to ensure the care and treatment of the sick.
In France, EDF, RTE and Enedis have taken all the necessary steps to ensure the continuity of electricity generation, transmission and distribution. The security of our electricity supply and the stability of the networks are not expected to be at risk during the current crisis. Similar measures to guarantee continuity of supply have been taken in all UCTE (Union for the Coordination of Transmission of Electricity) countries, linked through interconnections and the European electricity grid. Demand fell by about 10% due to the shutdown of part of the generating equipment.
«The security of our electricity supply and the stability of the networks are not expected to be at risk during the current crisis.»
Yet the risk of collapse of the French network has increased in recent years.
What is a blackout?
Since electricity is a flow of electrons in a conductive material, it is by definition not storable. This constraint obliges the system operator (in France, RTE) to constantly ensure a balance between production and consumption.
Consumption has always been variable. Production is also becoming variable, and increasingly so. Adjusting one to the other is therefore becoming an increasingly complex and risky exercise. An imbalance between consumption and production, if uncontrolled by grid operators, would lead to a decrease or increase in frequency which could cause the collapse of a national power system. Then, the entire continental grid could collapse like a house of cards.
To adjust production to demand, the manager has numerous regulation tools at his disposal, the first being the increase or decrease of the production of controllable power plants such as dams or thermal power plants (nuclear, fossil and biomass). These must adjust their production to the residual demand unmet by the energy produced by constant energies (1) (run-of-river hydropower, wind and photovoltaic).
«An imbalance between consumption and production, if uncontrolled by grid operators, would lead to a decrease or increase in frequency which could cause the collapse of a national power system. Then, the entire continental grid could collapse like a house of cards.»
A blackout – meaning, the collapse of the electrical system – would last at least several hours and would have serious repercussions in our ultra-electrified societies, especially in the middle of the day:
- No more light, heat, food cold chain or drinking water supply.
- No more means of communication of any kind – telephone, internet, computers, working from home, television, radio.
- No more supplies from food stores or pharmacies.
- No more rail traffic, air traffic, subways or trams.
- No more traffic lights. Total traffic jams, not only in cities but also on motorways due to blockages of toll booths and petrol stations.
- Shutdown of factories. Much of the production in progress would be scrapped.
- Impossibility for emergency services to circulate due to the blockage of urban and suburban traffic.
- In residential and office buildings, no more heating of any kind, no more refrigeration, no more lighting, no more aeration or ventilation, and the blocking of access in many cases due to non functioning of automatic doors and elevators.
Finally, the reconstruction of the network (“black-start” in the jargon of electricians) could take several days, and would rely mainly on hydroelectric dams and the few controllable means of production that would have managed to supply themselves in closed circuit (“islanding”).
What is the European situation and how does it impact France?
The French electricity system is interconnected with the electricity systems of the other countries on the European continental plate, from Dublin to Athens and from Lisbon to Bucharest, within the group known as UCTE. The stability of this plate is uncertain.
Many countries (France, Belgium, Germany) have already shut down some of their controllable means of production (coal and nuclear power plants), and plan to shut down more, thereby reducing the network operators’ room for manoeuvre. In France, the closure of the first reactor of the Fessenheim power plant in February, to be followed, according to plan, by the closure of the second one next June, and subsequently by several coal-fired power plants in the years to come, are contributing to this deterioration. RTE has also issued a warning (2) on the impact these closures will have on security of supply. For the period 2019-2022, the latter is estimated to be “adjusted as closely as possible to needs”, and “under vigilance” for the period 2022-2023.
On the other hand, the massive introduction of new intermittent means of production such as wind power and photovoltaics is becoming widespread. The combination of these two trends has considerably complicated the management of electricity grids.
As part of its energy transition (Energiewende), Germany has shut down many nuclear power plants and installed an intermittent renewable fleet whose output has exceeded that of all controllable facilities. But now it has to cope with increasingly higher power variations (or gradients).
One example: during the week from 15 April to 21 April 2019, the four German grid operators had to switch off and then restart some 30 GW of controllable capacity, each day, between 5 a.m. and 8 p.m., simply in order to cope with fluctuations in sunshine! 30 GW represents the start-up or shutdown of half of the French nuclear fleet!
«Exactly one year ago, the four German grid operators had to switch off and restart the equivalent of half of France’s nuclear power plants every day between 5 a.m. and 8 p.m. to cope with fluctuations in sunlight alone!»
On 19 April 2019 between 8 and 9 a.m., solar power grew by 7.5 GW in one hour (about the equivalent of the remaining German nuclear power capacity), and decreased by the same amount between 5 and 6 p.m. Wind power fluctuation is similar: Easter Monday (22 April 2019) recorded gradients of +13 GW/hour, then -10 GW/hour. These gradients are at the limit of what the stability of the European power system can withstand.
«These gradients are at the limit of what the stability of the European power system can withstand.»
The stability of the UCTE power system is based, firstly, on each country’s ability to manage its own controllable capacity, and secondly, on the ability of the interconnections to allow some to compensate for the limitations of others. But the latter possibilities are limited, and variations in sunshine and wind speeds are the same on all the west coasts. So the gradients measured in Germany can also occur simultaneously in Spain, France, Belgium and the Netherlands, and all can find themselves in difficulty at the same time. As more and more intermittent capabilities are introduced, what used to be a collective strength becomes increasingly a collective risk.
In order to reduce these violent gradients, grid operators can carry out “clipping”, i.e. they limit the electricity injected into the grids by disconnecting some of these intermittent sources.
Consequences of the ongoing health crisis for grid stability
The current health crisis does not affect the ability of companies to guarantee the continuity of the electricity supply service to the French people from the point of view of their organisation. These situations, however exceptional they may be, were anticipated and the organizations responsible were immediately configured to deal with them.
«In the context of the current health crisis, the difficulty comes from the combination of a significant drop in consumption and a large proportion of intermittent capacity on the network.»
The power demand is lower, which leads to the shutdown of several controllable sources while the variations in wind and photovoltaic power remain the same. The means for regulating the rise and fall of production are therefore even more limited than in normal times. In the context of the current health crisis, the difficulty comes from the combination of a significant drop in consumption and a large proportion of intermittent capacity on the network.
If the consequences of a Europe-wide blackout would very serious in normal times, they would be unimaginable in the current situation.
- All hospital services and city health services would break down. Hospitals and clinics are equipped with emergency power generators, but experience shows that not all of them are able to cope with the demand and that they have limited autonomy. Operating theatres and intensive care units would have serious problems.
- All manufacturing of protective equipment, ventilators and tests would stop, precisely at a time of extreme shortage.
- Isolated persons would be cut off from the outside world.
Maintaining controllable means of energy production is not only necessary to ensure grid stability and security of supply, but also to increase the resilience of our energy systems in the event of a major crisis such as the one we are experiencing today.
«Ensuring access to reliable, affordable and environmentally friendly electricity for all is one of the 17 United Nations sustainable development goals.»
Ensuring access to reliable, affordable and environmentally friendly electricity for all is one of the 17 United Nations sustainable development goals. In France, the public electricity service relies largely on nuclear and hydroelectric power plants which provide controllable electricity that is both cheap and low in greenhouse gas emissions over its entire lifecycle.
These means of production are an asset for France and for Europe, and it is up to each of us to help spread the word.
1 As these energies cannot be controlled, their production “imposes” itself on the network. They therefore have priority by default.
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